The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 18, 1978
Filed:
Aug. 15, 1977
Harold S Horowitz, Clark, NJ (US);
John M Longo, New Providence, NJ (US);
Exxon Research & Engineering Co., Linden, NJ (US);
Abstract
Mixed metal oxides of the formula CaMn.sub.3 O.sub.6, CaMn.sub.4 O.sub.8 and CaMn.sub.7 O.sub.12 are disclosed. They are useful in electrochemical processes. CaMn.sub.3 O.sub.6 is a mixed valence composition whose formula may be written as Ca[Mn.sub.2.sup.3+ Mn.sup.4+ ]O.sub.6. The compound is stable in H.sub.2 to about 400.degree. C. and in oxygen to approximately 925.degree. C. CaMn.sub.4 O.sub.8 is also a mixed valence composition whose formula may be written Ca[Mn.sub.2.sup.3+ Mn.sub.2.sup.4+ ]O.sub.8. This compound is stable in H.sub.2 to about 250.degree. C. and in O.sub.2 to about 900.degree. C. CaMn.sub.7 O.sub.12 is a mixed valence composition whose formula may be written as Ca[Mn.sup.4+ Mn.sub.6.sup.3+ ]O.sub.12. The compound is stable in H.sub.2 to about 500.degree. C. and in oxygen to approximately 950.degree. C. These materials may be prepared by a variety of standard ceramic techniques, among them being heating in oxygen a mixture of calcium oxide and manganese oxide or mixed calcium and manganese salts or calcium salt and manganese oxide, or calcium oxide and manganese salt. Alternatively, solid solutions of mixed calcium and manganese carbonates may be decomposed to the compositions. The mixed calcium-manganese carbonate solid solutions are prepared by the precipitation from salt solution of the calcium and manganese by the addition of an excess of an appropriate carbonate ion source such as (NH.sub.4).sub.2 CO.sub.3. The metal ion ratio in this salt solution is adjusted so that the resulting precipitate has the same stoichiometry as the desired oxide. The precipitate is calcined to yield the mixed metal oxide product described. The compounds described have utility as primary battery cathodes and also find use as oxygen activating catalysts in applications such as partial oxidation; methanol decomposition and oxygen reduction at a fuel cell cathode.